This invention relates to a method and an apparatus for the manufacture of sheets or board units from cellulose or wood fibrous material or shavings by heat and pressure in the interspaces between the press plates of a multi in which, a plurality of sheets simultaneously enter the individual interspaces.
It is known already to introduce sheets into a multi opening press in such a manner that one single sheet is caused to enter each interspace in the press. As saving of time always is an aim in this type of manufacture, it is of greatest importance to shorten as much as possible every working step in the production process. Therefore, it is one main object of the invention to provide a method and an apparatus which makes it possible substantially to shorten the time overall production. This object has been attained by increasing the average feed speed of the sheets according to the invention by introducing two or more sheets simultaneously into each interspace in the multi opening press.
A further object of the invention is to provide a method and an apparatus by which the capacity of the press is increased so that a greater number of sheets or board units can be produced in a single pressing operation with a press having a given height. The aforesaid objects of the invention are substantially realized by the steps of depositing the sheets on conveyor members, such as plates, platens, frames and the like, provided, if desired, with the wire cloth, thereupon stacking said conveyor members one upon the other by movement in vertical direction whereby an overlying conveyor member is brought to bear against the sheet resting on the immediately underlying conveyor member directly against the underlying conveyor member, and thereafter introducing the stacked assembly into a predetermined interspace in the press.
When carrying out the method according to the invention a novel stacking apparatus is utilized which substantially is characterized by a lifting and lowering device by means of which the conveyor members are vertically movable to, and away from, a support device located above a conveyor track, said device being adapted to catch and retain one or more conveyor members during the stacking operation.